CYMS came out hard at the start of Sunday's under 18s clash but the Forbes juniors rallied and claimed a convincing win at Spooner Oval on Sunday.
The visitors made a strong start to the game, scoring two quick tries and establishing an early 12-nil lead.
Forbes took a little time to settle into the game, with more than one handling error frustrating their fans, but once they did they quickly scored two of their own tries in response.
When the half-time bell went, it was Forbes in front.
CYMS were first to score in the second half but that was all the Magpies allowed. The host side piled on the points in the final 15 minutes for a convincing 42-20 win.
The junior Magpies remain undefeated and on top of their Group 11 table after four weeks of competition, but coach Jason Kennedy says their next two games will put them to the test.
Not excusing the errors at the start of Sunday's game, he said the side was good once they settled down.
"They knew what they had to do," he said.
"The halves, Tom Toohey and Toby Hurford, were outstanding," he added.
"And the back row, Harry Leadbitter, Jack Hartwig and Tom Phillips, worked all day."
Those promising young players were all part of the premiership-winning 2018 side, but there's some exciting new blood in the squad as well.
Centre Isaac Nash and front rower Charlie Hollman have both made great starts stepping up to the Under 18s, Kennedy said.
The Under 18s have a bye this weekend, then host Wellington at Spooner Oval and Kennedy expects the young Cowboys to present solid competition.
"They're travelling really well, we've got to be on our toes and ready," he said.
This weekend the senior grades head to Dubbo to meet Dubbo Westside.